/* src/common/port/crypt.cpp */
/*	$NetBSD: crypt.c,v 1.18 2001/03/01 14:37:35 wiz Exp $	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Tom Truscott.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *	  notice, this list of conditions and the following disclaimer in the
 *	  documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *	  may be used to endorse or promote products derived from this software
 *	  without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.	IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: crypt.c,v 1.18 2001/03/01 14:37:35 wiz Exp $");
#endif /* not lint */

#include "c.h"

#include <limits.h>

#ifndef WIN32
#include <unistd.h>
#endif

static int des_setkey(const char* key);
static int des_cipher(const char* in, char* out, long salt, int num_iter);

/*
 * UNIX password, and DES, encryption.
 * By Tom Truscott, trt@rti.rti.org,
 * from algorithms by Robert W. Baldwin and James Gillogly.
 *
 * References:
 * "Mathematical Cryptology for Computer Scientists and Mathematicians,"
 * by Wayne Patterson, 1987, ISBN 0-8476-7438-X.
 *
 * "Password Security: A Case History," R. Morris and Ken Thompson,
 * Communications of the ACM, vol. 22, pp. 594-597, Nov. 1979.
 *
 * "DES will be Totally Insecure within Ten Years," M.E. Hellman,
 * IEEE Spectrum, vol. 16, pp. 32-39, July 1979.
 */

/* =====  Configuration ==================== */

/*
 * define "MUST_ALIGN" if your compiler cannot load/store
 * long integers at arbitrary (e.g. odd) memory locations.
 * (Either that or never pass unaligned addresses to des_cipher!)
 */
#ifdef CHAR_BITS
#if CHAR_BITS != 8
#error C_block structure assumes 8 bit characters
#endif
#endif

/*
 * define "B64" to be the declaration for a 64 bit integer.
 * XXX this feature is currently unused, see "endian" comment below.
 */
#define B64 __int64

/*
 * define "LARGEDATA" to get faster permutations, by using about 72 kilobytes
 * of lookup tables.  This speeds up des_setkey() and des_cipher(), but has
 * little effect on crypt().
 */

/* compile with "-DSTATIC=void" when profiling */
#ifndef STATIC
#define STATIC static void
#endif

/*
 * Define the "int32_t" type for integral type with a width of at least
 * 32 bits.
 */
typedef int int32_t;

/* ==================================== */

#define _PASSWORD_EFMT1 '_' /* extended encryption format */

/*
 * Cipher-block representation (Bob Baldwin):
 *
 * DES operates on groups of 64 bits, numbered 1..64 (sigh).  One
 * representation is to store one bit per byte in an array of bytes.  Bit N of
 * the NBS spec is stored as the LSB of the Nth byte (index N-1) in the array.
 * Another representation stores the 64 bits in 8 bytes, with bits 1..8 in the
 * first byte, 9..16 in the second, and so on.	The DES spec apparently has
 * bit 1 in the MSB of the first byte, but that is particularly noxious so we
 * bit-reverse each byte so that bit 1 is the LSB of the first byte, bit 8 is
 * the MSB of the first byte.  Specifically, the 64-bit input data and key are
 * converted to LSB format, and the output 64-bit block is converted back into
 * MSB format.
 *
 * DES operates internally on groups of 32 bits which are expanded to 48 bits
 * by permutation E and shrunk back to 32 bits by the S boxes.	To speed up
 * the computation, the expansion is applied only once, the expanded
 * representation is maintained during the encryption, and a compression
 * permutation is applied only at the end.	To speed up the S-box lookups,
 * the 48 bits are maintained as eight 6 bit groups, one per byte, which
 * directly feed the eight S-boxes.  Within each byte, the 6 bits are the
 * most significant ones.  The low two bits of each byte are zero.	(Thus,
 * bit 1 of the 48 bit E expansion is stored as the "4"-valued bit of the
 * first byte in the eight byte representation, bit 2 of the 48 bit value is
 * the "8"-valued bit, and so on.)	In fact, a combined "SPE"-box lookup is
 * used, in which the output is the 64 bit result of an S-box lookup which
 * has been permuted by P and expanded by E, and is ready for use in the next
 * iteration.  Two 32-bit wide tables, SPE[0] and SPE[1], are used for this
 * lookup.	Since each byte in the 48 bit path is a multiple of four, indexed
 * lookup of SPE[0] and SPE[1] is simple and fast.	The key schedule and
 * "salt" are also converted to this 8*(6+2) format.  The SPE table size is
 * 8*64*8 = 4K bytes.
 *
 * To speed up bit-parallel operations (such as XOR), the 8 byte
 * representation is "union"ed with 32 bit values "i0" and "i1", and, on
 * machines which support it, a 64 bit value "b64".  This data structure,
 * "C_block", has two problems.  First, alignment restrictions must be
 * honored.  Second, the byte-order (e.g. little-endian or big-endian) of
 * the architecture becomes visible.
 *
 * The byte-order problem is unfortunate, since on the one hand it is good
 * to have a machine-independent C_block representation (bits 1..8 in the
 * first byte, etc.), and on the other hand it is good for the LSB of the
 * first byte to be the LSB of i0.	We cannot have both these things, so we
 * currently use the "little-endian" representation and avoid any multi-byte
 * operations that depend on byte order.  This largely precludes use of the
 * 64-bit datatype since the relative order of i0 and i1 are unknown.  It
 * also inhibits grouping the SPE table to look up 12 bits at a time.  (The
 * 12 bits can be stored in a 16-bit field with 3 low-order zeroes and 1
 * high-order zero, providing fast indexing into a 64-bit wide SPE.)  On the
 * other hand, 64-bit datatypes are currently rare, and a 12-bit SPE lookup
 * requires a 128 kilobyte table, so perhaps this is not a big loss.
 *
 * Permutation representation (Jim Gillogly):
 *
 * A transformation is defined by its effect on each of the 8 bytes of the
 * 64-bit input.  For each byte we give a 64-bit output that has the bits in
 * the input distributed appropriately.  The transformation is then the OR
 * of the 8 sets of 64-bits.  This uses 8*256*8 = 16K bytes of storage for
 * each transformation.  Unless LARGEDATA is defined, however, a more compact
 * table is used which looks up 16 4-bit "chunks" rather than 8 8-bit chunks.
 * The smaller table uses 16*16*8 = 2K bytes for each transformation.  This
 * is slower but tolerable, particularly for password encryption in which
 * the SPE transformation is iterated many times.  The small tables total 9K
 * bytes, the large tables total 72K bytes.
 *
 * The transformations used are:
 * IE3264: MSB->LSB conversion, initial permutation, and expansion.
 *	This is done by collecting the 32 even-numbered bits and applying
 *	a 32->64 bit transformation, and then collecting the 32 odd-numbered
 *	bits and applying the same transformation.	Since there are only
 *	32 input bits, the IE3264 transformation table is half the size of
 *	the usual table.
 * CF6464: Compression, final permutation, and LSB->MSB conversion.
 *	This is done by two trivial 48->32 bit compressions to obtain
 *	a 64-bit block (the bit numbering is given in the "CIFP" table)
 *	followed by a 64->64 bit "cleanup" transformation.	(It would
 *	be possible to group the bits in the 64-bit block so that 2
 *	identical 32->32 bit transformations could be used instead,
 *	saving a factor of 4 in space and possibly 2 in time, but
 *	byte-ordering and other complications rear their ugly head.
 *	Similar opportunities/problems arise in the key schedule
 *	transforms.)
 * PC1ROT: MSB->LSB, PC1 permutation, rotate, and PC2 permutation.
 *	This admittedly baroque 64->64 bit transformation is used to
 *	produce the first code (in 8*(6+2) format) of the key schedule.
 * PC2ROT[0]: Inverse PC2 permutation, rotate, and PC2 permutation.
 *	It would be possible to define 15 more transformations, each
 *	with a different rotation, to generate the entire key schedule.
 *	To save space, however, we instead permute each code into the
 *	next by using a transformation that "undoes" the PC2 permutation,
 *	rotates the code, and then applies PC2.  Unfortunately, PC2
 *	transforms 56 bits into 48 bits, dropping 8 bits, so PC2 is not
 *	invertible.  We get around that problem by using a modified PC2
 *	which retains the 8 otherwise-lost bits in the unused low-order
 *	bits of each byte.	The low-order bits are cleared when the
 *	codes are stored into the key schedule.
 * PC2ROT[1]: Same as PC2ROT[0], but with two rotations.
 *	This is faster than applying PC2ROT[0] twice,
 *
 * The Bell Labs "salt" (Bob Baldwin):
 *
 * The salting is a simple permutation applied to the 48-bit result of E.
 * Specifically, if bit i (1 <= i <= 24) of the salt is set then bits i and
 * i+24 of the result are swapped.	The salt is thus a 24 bit number, with
 * 16777216 possible values.  (The original salt was 12 bits and could not
 * swap bits 13..24 with 36..48.)
 *
 * It is possible, but ugly, to warp the SPE table to account for the salt
 * permutation.  Fortunately, the conditional bit swapping requires only
 * about four machine instructions and can be done on-the-fly with about an
 * 8% performance penalty.
 */

typedef union {
    unsigned char b[8];
    struct {
        int32_t i0;
        int32_t i1;
    } b32;
#if defined(B64)
    int64 b64;
#endif
} C_block;

/*
 * Convert twenty-four-bit long in host-order
 * to six bits (and 2 low-order zeroes) per char little-endian format.
 */
#define TO_SIX_BIT(rslt, src)                     \
    {                                             \
        C_block cvt;                              \
        cvt.b[0] = (src);                         \
        (src) >>= 6;                              \
        cvt.b[1] = (src);                         \
        (src) >>= 6;                              \
        cvt.b[2] = (src);                         \
        (src) >>= 6;                              \
        cvt.b[3] = (src);                         \
        (rslt) = (cvt.b32.i0 & 0x3f3f3f3fL) << 2; \
    }

/*
 * These macros may someday permit efficient use of 64-bit integers.
 */
#define ZERO(d, d0, d1) (d0) = 0, (d1) = 0
#define LOAD(d, d0, d1, bl) (d0) = (bl).b32.i0, (d1) = (bl).b32.i1
#define LOADREG(d, d0, d1, s, s0, s1) (d0) = (s0), (d1) = (s1)
#define OR(d, d0, d1, bl) (d0) |= (bl).b32.i0, (d1) |= (bl).b32.i1
#define STORE(s, s0, s1, bl) (bl).b32.i0 = (s0), (bl).b32.i1 = (s1)
#define DCL_BLOCK(d, d0, d1) int32_t d0, d1

#if defined(LARGEDATA)
/* Waste memory like crazy.  Also, do permutations in line */
#define LGCHUNKBITS 3
#define CHUNKBITS (1 << LGCHUNKBITS)
#define PERM6464(d, d0, d1, cpp, p)                    \
    LOAD(d, d0, d1, (p)[(0 << CHUNKBITS) + (cpp)[0]]); \
    OR(d, d0, d1, (p)[(1 << CHUNKBITS) + (cpp)[1]]);   \
    OR(d, d0, d1, (p)[(2 << CHUNKBITS) + (cpp)[2]]);   \
    OR(d, d0, d1, (p)[(3 << CHUNKBITS) + (cpp)[3]]);   \
    OR(d, d0, d1, (p)[(4 << CHUNKBITS) + (cpp)[4]]);   \
    OR(d, d0, d1, (p)[(5 << CHUNKBITS) + (cpp)[5]]);   \
    OR(d, d0, d1, (p)[(6 << CHUNKBITS) + (cpp)[6]]);   \
    OR(d, d0, d1, (p)[(7 << CHUNKBITS) + (cpp)[7]]);
#define PERM3264(d, d0, d1, cpp, p)                    \
    LOAD(d, d0, d1, (p)[(0 << CHUNKBITS) + (cpp)[0]]); \
    OR(d, d0, d1, (p)[(1 << CHUNKBITS) + (cpp)[1]]);   \
    OR(d, d0, d1, (p)[(2 << CHUNKBITS) + (cpp)[2]]);   \
    OR(d, d0, d1, (p)[(3 << CHUNKBITS) + (cpp)[3]]);
#else
/* "small data" */
#define LGCHUNKBITS 2
#define CHUNKBITS (1 << LGCHUNKBITS)
#define PERM6464(d, d0, d1, cpp, p) \
    {                               \
        C_block tblk;               \
        permute(cpp, &tblk, p, 8);  \
        LOAD(d, d0, d1, tblk);      \
    }
#define PERM3264(d, d0, d1, cpp, p) \
    {                               \
        C_block tblk;               \
        permute(cpp, &tblk, p, 4);  \
        LOAD(d, d0, d1, tblk);      \
    }
#endif /* LARGEDATA */

STATIC init_des(void);
STATIC init_perm(C_block[64 / CHUNKBITS][1 << CHUNKBITS], unsigned char[64], int, int);

#ifndef LARGEDATA
STATIC permute(unsigned char*, C_block*, C_block*, int);
#endif
#ifdef DEBUG
STATIC prtab(char*, unsigned char*, int);
#endif

#ifndef LARGEDATA
#ifdef WIN32
STATIC permute(unsigned char* cp, C_block* out, C_block* p, int chars_in)
#else
STATIC permute(unsigned char* cp, C_block* out, C_block* p, int chars_in)
#endif /* WIN32 */
{
    DCL_BLOCK(D, D0, D1);
    C_block* tp = NULL;
    int t;

    ZERO(D, D0, D1);
    do {
        t = *cp++;
        tp = &p[t & 0xf];
        OR(D, D0, D1, *tp);
        p += (1 << CHUNKBITS);
        tp = &p[t >> 4];
        OR(D, D0, D1, *tp);
        p += (1 << CHUNKBITS);
    } while (--chars_in > 0);
    STORE(D, D0, D1, *out);
}
#endif /* LARGEDATA */

/* =====  (mostly) Standard DES Tables ==================== */

static const unsigned char IP[] = {
    /* initial permutation */
    58,
    50,
    42,
    34,
    26,
    18,
    10,
    2,
    60,
    52,
    44,
    36,
    28,
    20,
    12,
    4,
    62,
    54,
    46,
    38,
    30,
    22,
    14,
    6,
    64,
    56,
    48,
    40,
    32,
    24,
    16,
    8,
    57,
    49,
    41,
    33,
    25,
    17,
    9,
    1,
    59,
    51,
    43,
    35,
    27,
    19,
    11,
    3,
    61,
    53,
    45,
    37,
    29,
    21,
    13,
    5,
    63,
    55,
    47,
    39,
    31,
    23,
    15,
    7,
};

/* The final permutation is the inverse of IP - no table is necessary */

static const unsigned char ExpandTr[] = {
    /* expansion operation */
    32,
    1,
    2,
    3,
    4,
    5,
    4,
    5,
    6,
    7,
    8,
    9,
    8,
    9,
    10,
    11,
    12,
    13,
    12,
    13,
    14,
    15,
    16,
    17,
    16,
    17,
    18,
    19,
    20,
    21,
    20,
    21,
    22,
    23,
    24,
    25,
    24,
    25,
    26,
    27,
    28,
    29,
    28,
    29,
    30,
    31,
    32,
    1,
};

static const unsigned char PC1[] = {
    /* permuted choice table 1 */
    57,
    49,
    41,
    33,
    25,
    17,
    9,
    1,
    58,
    50,
    42,
    34,
    26,
    18,
    10,
    2,
    59,
    51,
    43,
    35,
    27,
    19,
    11,
    3,
    60,
    52,
    44,
    36,

    63,
    55,
    47,
    39,
    31,
    23,
    15,
    7,
    62,
    54,
    46,
    38,
    30,
    22,
    14,
    6,
    61,
    53,
    45,
    37,
    29,
    21,
    13,
    5,
    28,
    20,
    12,
    4,
};

static const unsigned char Rotates[] = {
    /* PC1 rotation schedule */
    1,
    1,
    2,
    2,
    2,
    2,
    2,
    2,
    1,
    2,
    2,
    2,
    2,
    2,
    2,
    1,
};

/* note: each "row" of PC2 is left-padded with bits that make it invertible */
static const unsigned char PC2[] = {
    /* permuted choice table 2 */
    9,
    18,
    14,
    17,
    11,
    24,
    1,
    5,
    22,
    25,
    3,
    28,
    15,
    6,
    21,
    10,
    35,
    38,
    23,
    19,
    12,
    4,
    26,
    8,
    43,
    54,
    16,
    7,
    27,
    20,
    13,
    2,

    0,
    0,
    41,
    52,
    31,
    37,
    47,
    55,
    0,
    0,
    30,
    40,
    51,
    45,
    33,
    48,
    0,
    0,
    44,
    49,
    39,
    56,
    34,
    53,
    0,
    0,
    46,
    42,
    50,
    36,
    29,
    32,
};

static const unsigned char S[8][64] = {/* 48->32 bit substitution tables */
    /* S[1]			*/
    {14,
        4,
        13,
        1,
        2,
        15,
        11,
        8,
        3,
        10,
        6,
        12,
        5,
        9,
        0,
        7,
        0,
        15,
        7,
        4,
        14,
        2,
        13,
        1,
        10,
        6,
        12,
        11,
        9,
        5,
        3,
        8,
        4,
        1,
        14,
        8,
        13,
        6,
        2,
        11,
        15,
        12,
        9,
        7,
        3,
        10,
        5,
        0,
        15,
        12,
        8,
        2,
        4,
        9,
        1,
        7,
        5,
        11,
        3,
        14,
        10,
        0,
        6,
        13},
    /* S[2]			*/
    {15,
        1,
        8,
        14,
        6,
        11,
        3,
        4,
        9,
        7,
        2,
        13,
        12,
        0,
        5,
        10,
        3,
        13,
        4,
        7,
        15,
        2,
        8,
        14,
        12,
        0,
        1,
        10,
        6,
        9,
        11,
        5,
        0,
        14,
        7,
        11,
        10,
        4,
        13,
        1,
        5,
        8,
        12,
        6,
        9,
        3,
        2,
        15,
        13,
        8,
        10,
        1,
        3,
        15,
        4,
        2,
        11,
        6,
        7,
        12,
        0,
        5,
        14,
        9},
    /* S[3]			*/
    {10,
        0,
        9,
        14,
        6,
        3,
        15,
        5,
        1,
        13,
        12,
        7,
        11,
        4,
        2,
        8,
        13,
        7,
        0,
        9,
        3,
        4,
        6,
        10,
        2,
        8,
        5,
        14,
        12,
        11,
        15,
        1,
        13,
        6,
        4,
        9,
        8,
        15,
        3,
        0,
        11,
        1,
        2,
        12,
        5,
        10,
        14,
        7,
        1,
        10,
        13,
        0,
        6,
        9,
        8,
        7,
        4,
        15,
        14,
        3,
        11,
        5,
        2,
        12},
    /* S[4]			*/
    {7,
        13,
        14,
        3,
        0,
        6,
        9,
        10,
        1,
        2,
        8,
        5,
        11,
        12,
        4,
        15,
        13,
        8,
        11,
        5,
        6,
        15,
        0,
        3,
        4,
        7,
        2,
        12,
        1,
        10,
        14,
        9,
        10,
        6,
        9,
        0,
        12,
        11,
        7,
        13,
        15,
        1,
        3,
        14,
        5,
        2,
        8,
        4,
        3,
        15,
        0,
        6,
        10,
        1,
        13,
        8,
        9,
        4,
        5,
        11,
        12,
        7,
        2,
        14},
    /* S[5]			*/
    {2,
        12,
        4,
        1,
        7,
        10,
        11,
        6,
        8,
        5,
        3,
        15,
        13,
        0,
        14,
        9,
        14,
        11,
        2,
        12,
        4,
        7,
        13,
        1,
        5,
        0,
        15,
        10,
        3,
        9,
        8,
        6,
        4,
        2,
        1,
        11,
        10,
        13,
        7,
        8,
        15,
        9,
        12,
        5,
        6,
        3,
        0,
        14,
        11,
        8,
        12,
        7,
        1,
        14,
        2,
        13,
        6,
        15,
        0,
        9,
        10,
        4,
        5,
        3},
    /* S[6]			*/
    {12,
        1,
        10,
        15,
        9,
        2,
        6,
        8,
        0,
        13,
        3,
        4,
        14,
        7,
        5,
        11,
        10,
        15,
        4,
        2,
        7,
        12,
        9,
        5,
        6,
        1,
        13,
        14,
        0,
        11,
        3,
        8,
        9,
        14,
        15,
        5,
        2,
        8,
        12,
        3,
        7,
        0,
        4,
        10,
        1,
        13,
        11,
        6,
        4,
        3,
        2,
        12,
        9,
        5,
        15,
        10,
        11,
        14,
        1,
        7,
        6,
        0,
        8,
        13},
    /* S[7]			*/
    {4,
        11,
        2,
        14,
        15,
        0,
        8,
        13,
        3,
        12,
        9,
        7,
        5,
        10,
        6,
        1,
        13,
        0,
        11,
        7,
        4,
        9,
        1,
        10,
        14,
        3,
        5,
        12,
        2,
        15,
        8,
        6,
        1,
        4,
        11,
        13,
        12,
        3,
        7,
        14,
        10,
        15,
        6,
        8,
        0,
        5,
        9,
        2,
        6,
        11,
        13,
        8,
        1,
        4,
        10,
        7,
        9,
        5,
        0,
        15,
        14,
        2,
        3,
        12},
    /* S[8]			*/
    {13,
        2,
        8,
        4,
        6,
        15,
        11,
        1,
        10,
        9,
        3,
        14,
        5,
        0,
        12,
        7,
        1,
        15,
        13,
        8,
        10,
        3,
        7,
        4,
        12,
        5,
        6,
        11,
        0,
        14,
        9,
        2,
        7,
        11,
        4,
        1,
        9,
        12,
        14,
        2,
        0,
        6,
        10,
        13,
        15,
        3,
        5,
        8,
        2,
        1,
        14,
        7,
        4,
        10,
        8,
        13,
        15,
        12,
        9,
        0,
        3,
        5,
        6,
        11}};

static const unsigned char P32Tr[] = {
    /* 32-bit permutation function */
    16,
    7,
    20,
    21,
    29,
    12,
    28,
    17,
    1,
    15,
    23,
    26,
    5,
    18,
    31,
    10,
    2,
    8,
    24,
    14,
    32,
    27,
    3,
    9,
    19,
    13,
    30,
    6,
    22,
    11,
    4,
    25,
};

static const unsigned char CIFP[] = {
    /* compressed/interleaved permutation */
    1,
    2,
    3,
    4,
    17,
    18,
    19,
    20,
    5,
    6,
    7,
    8,
    21,
    22,
    23,
    24,
    9,
    10,
    11,
    12,
    25,
    26,
    27,
    28,
    13,
    14,
    15,
    16,
    29,
    30,
    31,
    32,

    33,
    34,
    35,
    36,
    49,
    50,
    51,
    52,
    37,
    38,
    39,
    40,
    53,
    54,
    55,
    56,
    41,
    42,
    43,
    44,
    57,
    58,
    59,
    60,
    45,
    46,
    47,
    48,
    61,
    62,
    63,
    64,
};

static const unsigned char itoa64[] = /* 0..63 => ascii-64 */
    "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

/* =====  Tables that are initialized at run time  ==================== */
static unsigned char a64toi[128]; /* ascii-64 => 0..63 */

/* Initial key schedule permutation */
static C_block PC1ROT[64 / CHUNKBITS][1 << CHUNKBITS];

/* Subsequent key schedule rotation permutations */
static C_block PC2ROT[2][64 / CHUNKBITS][1 << CHUNKBITS];

/* Initial permutation/expansion table */
static C_block IE3264[32 / CHUNKBITS][1 << CHUNKBITS];

/* Table that combines the S, P, and E operations.	*/
static int32_t SPE[2][8][64];

/* compressed/interleaved => final permutation table */
static C_block CF6464[64 / CHUNKBITS][1 << CHUNKBITS];

static C_block constdatablock;         /* encryption constant */
static THR_LOCAL char cryptresult[21]; /* encrypted result (1 + 4 + 4 + 11 + 1)*/

extern char* __md5crypt(const char*, const char*); /* XXX */
extern char* __bcrypt(const char*, const char*);   /* XXX */

/*
 * Return a pointer to static data consisting of the "setting"
 * followed by an encryption produced by the "key" and "setting".
 */
#ifdef WIN32
char* crypt(const char* key, const char* setting)
#else
char* crypt(const char* key, const char* setting) throw()
#endif /* WIN32 */
{
    char* encp = NULL;
    int32_t i;
    int t;
    int32_t salt;
    int num_iter, salt_size;
    C_block keyblock, rsltblock;

    for (i = 0; i < 8; i++) {
        if ((t = 2 * (unsigned char)(*key)) != 0) {
            key++;
        }
        keyblock.b[i] = t;
    }
    if (des_setkey((char*)keyblock.b)) { /* also initializes "a64toi" */
        return (NULL);
    }

    encp = &cryptresult[0];
    switch (*setting) {
        case _PASSWORD_EFMT1:

            /*
             * Involve the rest of the password 8 characters at a time.
             */
            while (*key) {
                if (des_cipher((char*)(void*)&keyblock, (char*)(void*)&keyblock, 0L, 1)) {
                    return (NULL);
                }
                for (i = 0; i < 8; i++) {
                    if ((t = 2 * (unsigned char)(*key)) != 0) {
                        key++;
                    }
                    keyblock.b[i] ^= t;
                }
                if (des_setkey((char*)keyblock.b)) {
                    return (NULL);
                }
            }

            *encp++ = *setting++;

            /* get iteration count */
            num_iter = 0;
            for (i = 4; --i >= 0;) {
                if ((t = (unsigned char)setting[i]) == '\0') {
                    t = '.';
                }
                encp[i] = t;
                num_iter = (num_iter << 6) | a64toi[t];
            }
            setting += 4;
            encp += 4;
            salt_size = 4;
            break;
        default:
            num_iter = 25;
            salt_size = 2;
            break;
    }

    salt = 0;
    for (i = salt_size; --i >= 0;) {
        if ((t = (unsigned char)setting[i]) == '\0') {
            t = '.';
        }
        encp[i] = t;
        salt = (salt << 6) | a64toi[t];
    }
    encp += salt_size;
    if (des_cipher((char*)(void*)&constdatablock, (char*)(void*)&rsltblock, salt, num_iter)) {
        return (NULL);
    }

    /*
     * Encode the 64 cipher bits as 11 ascii characters.
     */
    i = ((int32_t)((rsltblock.b[0] << 8) | rsltblock.b[1]) << 8) | rsltblock.b[2];
    encp[3] = itoa64[i & 0x3f];
    i >>= 6;
    encp[2] = itoa64[i & 0x3f];
    i >>= 6;
    encp[1] = itoa64[i & 0x3f];
    i >>= 6;
    encp[0] = itoa64[i];
    encp += 4;
    i = ((int32_t)((rsltblock.b[3] << 8) | rsltblock.b[4]) << 8) | rsltblock.b[5];
    encp[3] = itoa64[i & 0x3f];
    i >>= 6;
    encp[2] = itoa64[i & 0x3f];
    i >>= 6;
    encp[1] = itoa64[i & 0x3f];
    i >>= 6;
    encp[0] = itoa64[i];
    encp += 4;
    i = ((int32_t)((rsltblock.b[6]) << 8) | rsltblock.b[7]) << 2;
    encp[2] = itoa64[i & 0x3f];
    i >>= 6;
    encp[1] = itoa64[i & 0x3f];
    i >>= 6;
    encp[0] = itoa64[i];

    encp[3] = 0;

    return (cryptresult);
}

/*
 * The Key Schedule, filled in by des_setkey() or setkey().
 */
#define KS_SIZE 16
static C_block KS[KS_SIZE];

static volatile int des_ready = 0;

/*
 * Set up the key schedule from the key.
 */
#ifdef WIN32
static int des_setkey(const char* key)
#else
static int des_setkey(const char* key)
#endif /* WIN32 */
{
    DCL_BLOCK(K, K0, K1);
    C_block* ptabp = NULL;
    int i;

    if (!des_ready) {
        init_des();
    }

    PERM6464(K, K0, K1, (unsigned char*)key, (C_block*)PC1ROT);
    key = (char*)&KS[0];
    STORE(K & ~0x03030303L, K0 & ~0x03030303L, K1, *(C_block*)key);
    for (i = 1; i < 16; i++) {
        key += sizeof(C_block);
        STORE(K, K0, K1, *(C_block*)key);
        ptabp = (C_block*)PC2ROT[Rotates[i] - 1];
        PERM6464(K, K0, K1, (unsigned char*)key, ptabp);
        STORE(K & ~0x03030303L, K0 & ~0x03030303L, K1, *(C_block*)key);
    }
    return (0);
}

/*
 * Encrypt (or decrypt if num_iter < 0) the 8 chars at "in" with abs(num_iter)
 * iterations of DES, using the given 24-bit salt and the pre-computed key
 * schedule, and store the resulting 8 chars at "out" (in == out is permitted).
 *
 * NOTE: the performance of this routine is critically dependent on your
 * compiler and machine architecture.
 */
#ifdef WIN32
static int des_cipher(const char* in, char* out, long salt, int num_iter)
#else
static int des_cipher(const char* in, char* out, long salt, int num_iter)
#endif /* WIN32 */
{
    /* variables that we want in registers, most important first */
#if defined(pdp11)
    int j;
#endif
    int32_t L0, L1, R0, R1, k;
    C_block* kp = NULL;
    int ks_inc, loop_count;
    C_block B;

    L0 = salt;
    TO_SIX_BIT(salt, L0); /* convert to 4*(6+2) format */

#if defined(__vax__) || defined(pdp11)
    salt = ~salt; /* "x &~ y" is faster than "x & y". */
#define SALT (~salt)
#else
#define SALT salt
#endif

#if defined(MUST_ALIGN)
    B.b[0] = in[0];
    B.b[1] = in[1];
    B.b[2] = in[2];
    B.b[3] = in[3];
    B.b[4] = in[4];
    B.b[5] = in[5];
    B.b[6] = in[6];
    B.b[7] = in[7];
    LOAD(L, L0, L1, B);
#else
    LOAD(L, L0, L1, *(C_block*)in);
#endif
    LOADREG(R, R0, R1, L, L0, L1);
    L0 &= 0x55555555L;
    L1 &= 0x55555555L;
    L0 = (L0 << 1) | L1; /* L0 is the even-numbered input bits */
    R0 &= 0xaaaaaaaaL;
    R1 = (R1 >> 1) & 0x55555555L;
    L1 = R0 | R1; /* L1 is the odd-numbered input bits */
    STORE(L, L0, L1, B);
    PERM3264(L, L0, L1, B.b, (C_block*)IE3264);     /* even bits */
    PERM3264(R, R0, R1, B.b + 4, (C_block*)IE3264); /* odd bits */

    if (num_iter >= 0) { /* encryption */
        kp = &KS[0];
        ks_inc = sizeof(*kp);
    } else { /* decryption */
        num_iter = -num_iter;
        kp = &KS[KS_SIZE - 1];
        ks_inc = -(long)sizeof(*kp);
    }

    while (--num_iter >= 0) {
        loop_count = 8;
        do {

#define SPTAB(t, i) (*(int32_t*)((unsigned char*)(t) + (i) * (sizeof(int32_t) / 4)))
#if defined(gould)
            /* use this if B.b[i] is evaluated just once ... */
#define DOXOR(x, y, i)               \
    (x) ^= SPTAB(SPE[0][i], B.b[i]); \
    (y) ^= SPTAB(SPE[1][i], B.b[i]);
#else
#if defined(pdp11)
            /* use this if your "long" int indexing is slow */
#define DOXOR(x, y, i)          \
    j = B.b[i];                 \
    (x) ^= SPTAB(SPE[0][i], j); \
    (y) ^= SPTAB(SPE[1][i], j);
#else
            /* use this if "k" is allocated to a register ... */
#define DOXOR(x, y, i)          \
    k = B.b[i];                 \
    (x) ^= SPTAB(SPE[0][i], k); \
    (y) ^= SPTAB(SPE[1][i], k);
#endif
#endif

#define CRUNCH(p0, p1, q0, q1)           \
    k = ((q0) ^ (q1)) & SALT;            \
    B.b32.i0 = k ^ (q0) ^ kp->b32.i0;    \
    B.b32.i1 = k ^ (q1) ^ kp->b32.i1;    \
    kp = (C_block*)((char*)kp + ks_inc); \
                                         \
    DOXOR(p0, p1, 0);                    \
    DOXOR(p0, p1, 1);                    \
    DOXOR(p0, p1, 2);                    \
    DOXOR(p0, p1, 3);                    \
    DOXOR(p0, p1, 4);                    \
    DOXOR(p0, p1, 5);                    \
    DOXOR(p0, p1, 6);                    \
    DOXOR(p0, p1, 7);

            CRUNCH(L0, L1, R0, R1);
            CRUNCH(R0, R1, L0, L1);
        } while (--loop_count != 0);
        kp = (C_block*)((char*)kp - (ks_inc * KS_SIZE));

        /* swap L and R */
        L0 ^= R0;
        L1 ^= R1;
        R0 ^= L0;
        R1 ^= L1;
        L0 ^= R0;
        L1 ^= R1;
    }

    /* store the encrypted (or decrypted) result */
    L0 = ((L0 >> 3) & 0x0f0f0f0fL) | ((L1 << 1) & 0xf0f0f0f0L);
    L1 = ((R0 >> 3) & 0x0f0f0f0fL) | ((R1 << 1) & 0xf0f0f0f0L);
    STORE(L, L0, L1, B);
    PERM6464(L, L0, L1, B.b, (C_block*)CF6464);
#if defined(MUST_ALIGN)
    STORE(L, L0, L1, B);
    out[0] = B.b[0];
    out[1] = B.b[1];
    out[2] = B.b[2];
    out[3] = B.b[3];
    out[4] = B.b[4];
    out[5] = B.b[5];
    out[6] = B.b[6];
    out[7] = B.b[7];
#else
    STORE(L, L0, L1, *(C_block*)out);
#endif
    return (0);
}

/*
 * Initialize various tables.  This need only be done once.  It could even be
 * done at compile time, if the compiler were capable of that sort of thing.
 */
STATIC init_des()
{
    int i, j;
    int32_t k;
    int tableno;
    static unsigned char perm[64], tmp32[32]; /* "static" for speed */

    /*
     * table that converts chars "./0-9A-Za-z"to integers 0-63.
     */
    for (i = 0; i < 64; i++) {
        a64toi[itoa64[i]] = i;
    }

    /*
     * PC1ROT - bit reverse, then PC1, then Rotate, then PC2.
     */
    for (i = 0; i < 64; i++) {
        perm[i] = 0;
    }
    for (i = 0; i < 64; i++) {
        if ((k = PC2[i]) == 0) {
            continue;
        }
        k += Rotates[0] - 1;
        if ((k % 28) < Rotates[0]) {
            k -= 28;
        }
        k = PC1[k];
        if (k > 0) {
            k--;
            k = (k | 07) - (k & 07);
            k++;
        }
        perm[i] = k;
    }
#ifdef DEBUG
    prtab("pc1tab", perm, 8);
#endif
    init_perm(PC1ROT, perm, 8, 8);

    /*
     * PC2ROT - PC2 inverse, then Rotate (once or twice), then PC2.
     */
    for (j = 0; j < 2; j++) {
        unsigned char pc2inv[64];

        for (i = 0; i < 64; i++) {
            perm[i] = pc2inv[i] = 0;
        }
        for (i = 0; i < 64; i++) {
            if ((k = PC2[i]) == 0) {
                continue;
            }
            pc2inv[k - 1] = i + 1;
        }
        for (i = 0; i < 64; i++) {
            if ((k = PC2[i]) == 0) {
                continue;
            }
            k += j;
            if ((k % 28) <= j) {
                k -= 28;
            }
            perm[i] = pc2inv[k];
        }
#ifdef DEBUG
        prtab("pc2tab", perm, 8);
#endif
        init_perm(PC2ROT[j], perm, 8, 8);
    }

    /*
     * Bit reverse, then initial permutation, then expansion.
     */
    for (i = 0; i < 8; i++) {
        for (j = 0; j < 8; j++) {
            k = (j < 2) ? 0 : IP[ExpandTr[i * 6 + j - 2] - 1];
            if (k > 32) {
                k -= 32;
            } else if (k > 0) {
                k--;
            }
            if (k > 0) {
                k--;
                k = (k | 07) - (k & 07);
                k++;
            }
            perm[i * 8 + j] = k;
        }
    }
#ifdef DEBUG
    prtab("ietab", perm, 8);
#endif
    init_perm(IE3264, perm, 4, 8);

    /*
     * Compression, then final permutation, then bit reverse.
     */
    for (i = 0; i < 64; i++) {
        k = IP[CIFP[i] - 1];
        if (k > 0) {
            k--;
            k = (k | 07) - (k & 07);
            k++;
        }
        perm[k - 1] = i + 1;
    }
#ifdef DEBUG
    prtab("cftab", perm, 8);
#endif
    init_perm(CF6464, perm, 8, 8);

    /*
     * SPE table
     */
    for (i = 0; i < 48; i++) {
        perm[i] = P32Tr[ExpandTr[i] - 1];
    }
    for (tableno = 0; tableno < 8; tableno++) {
        for (j = 0; j < 64; j++) {
            k = (((j >> 0) & 01) << 5) | (((j >> 1) & 01) << 3) | (((j >> 2) & 01) << 2) | (((j >> 3) & 01) << 1) |
                (((j >> 4) & 01) << 0) | (((j >> 5) & 01) << 4);
            k = S[tableno][k];
            k = (((k >> 3) & 01) << 0) | (((k >> 2) & 01) << 1) | (((k >> 1) & 01) << 2) | (((k >> 0) & 01) << 3);
            for (i = 0; i < 32; i++) {
                tmp32[i] = 0;
            }
            for (i = 0; i < 4; i++) {
                tmp32[4 * tableno + i] = (k >> i) & 01;
            }
            k = 0;
            for (i = 24; --i >= 0;) {
                k = (k << 1) | tmp32[perm[i] - 1];
            }
            TO_SIX_BIT(SPE[0][tableno][j], k);
            k = 0;
            for (i = 24; --i >= 0;) {
                k = (k << 1) | tmp32[perm[i + 24] - 1];
            }
            TO_SIX_BIT(SPE[1][tableno][j], k);
        }
    }

    des_ready = 1;
}

/*
 * Initialize "perm" to represent transformation "p", which rearranges
 * (perhaps with expansion and/or contraction) one packed array of bits
 * (of size "chars_in" characters) into another array (of size "chars_out"
 * characters).
 *
 * "perm" must be all-zeroes on entry to this routine.
 */
#ifdef WIN32
STATIC init_perm(C_block perm[64 / CHUNKBITS][1 << CHUNKBITS], unsigned char p[64], int chars_in, int chars_out)
#else
STATIC init_perm(C_block perm[64 / CHUNKBITS][1 << CHUNKBITS], unsigned char p[64], int chars_in, int chars_out)
#endif /* WIN32 */
{
    int i, j, k, l;

    for (k = 0; k < chars_out * 8; k++) { /* each output bit position */
        l = p[k] - 1;                     /* where this bit comes from */
        if (l < 0) {
            continue; /* output bit is always 0 */
        }
        i = l >> LGCHUNKBITS;                    /* which chunk this bit comes from */
        l = 1 << (l & (CHUNKBITS - 1));          /* mask for this bit */
        for (j = 0; j < (1 << CHUNKBITS); j++) { /* each chunk value */
            if ((j & l) != 0) {
                perm[i][j].b[k >> 3] |= 1 << (k & 07);
            }
        }
    }
}

/*
 * "setkey" routine (for backwards compatibility)
 */
#ifdef NOT_USED
#ifdef WIN32
int setkey(const char* key)
#else
int setkey(const char* key)
#endif /*WIN32*/
{
    int i, j, k;
    C_block keyblock;

    for (i = 0; i < 8; i++) {
        k = 0;
        for (j = 0; j < 8; j++) {
            k <<= 1;
            k |= (unsigned char)*key++;
        }
        keyblock.b[i] = k;
    }
    return (des_setkey((char*)keyblock.b));
}

/*
 * "encrypt" routine (for backwards compatibility)
 */
#ifdef WIN32
static int encrypt(char* block, int flag)
#else
static int encrypt(char* block, int flag)
#endif /*WIN32*/
{
    int i, j, k;
    C_block cblock;

    for (i = 0; i < 8; i++) {
        k = 0;
        for (j = 0; j < 8; j++) {
            k <<= 1;
            k |= (unsigned char)*block++;
        }
        cblock.b[i] = k;
    }
    if (des_cipher((char*)&cblock, (char*)&cblock, 0L, (flag ? -1 : 1))) {
        return (1);
    }
    for (i = 7; i >= 0; i--) {
        k = cblock.b[i];
        for (j = 7; j >= 0; j--) {
            *--block = k & 01;
            k >>= 1;
        }
    }
    return (0);
}
#endif

#ifdef DEBUG
#ifdef WIN32
STATIC prtab(char* s, unsigned char* t, int num_rows)
#else
STATIC prtab(char* s, unsigned char* t, int num_rows)
#endif /* WIN32 */
{
    int i, j;

    (void)printf("%s:\n", s);
    for (i = 0; i < num_rows; i++) {
        for (j = 0; j < 8; j++) {
            (void)printf("%3d", t[i * 8 + j]);
        }
        (void)printf("\n");
    }
    (void)printf("\n");
}

#endif
